All browsers now include a “favorite” service which stores a list comprising the Uniform Resource Locator (URL) of the user's favorite web pages. However, the content or the URL of the web pages could be changed or updated as time goes by and there is a need to monitor the changes related to a bookmarked web page.
The work that has been done to monitor the changes or updates in web pages is oriented toward methods and systems comprising a tool which allows a user to monitor his/her favorite web sites by notifying the user if new content is found in these web sites.
There are also known methods and systems, such as those described in US patent application US 2003/0005041, to store in a centralized server a historical sequence of the monitored bookmarked web page and previous versions of a monitored bookmarked web page. These methods allows a user to select one of the previous versions of a bookmarked web page or document.
Nevertheless, the known methods, systems and apparatus are very resource consuming. Indeed, in these systems a centralized server is needed to poll all the web servers associated with the bookmarked web pages and to inform the users' browsers of any change within the bookmarked web pages. When there are a large number of bookmarked web pages then the resources needed by the centralized server to poll all the web pages are very substantial. So the known methods, systems and apparatus become more and more resource consuming with the increase of users and the number of bookmarked web pages.